Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method of operating a User Equipment (UE) in a wireless communication system and the UE using the same.
Related Art
3rd Generation Partnership Project (3GPP) long term evolution (LTE), which is improved technology of Universal Mobile Telecommunications System (UMTS) has been introduced to 3GPP release 8. 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink and uses Single Carrier-frequency division multiple access (SC-FDMA) in an uplink. Nowadays, a discussion on 3GPP LTE-Advanced (LTE-A), which is improved technology of 3GPP LTE has been performed.
A wireless communication system may provide a service to a UE through a plurality of access networks. For example, the UE may receive a service from a 3GPP access network, which is a mobile wireless communication system and receive a service from a non-3GPP access network such as Worldwide Interoperability for Microwave Access (WiMAX) and a Wireless Local Area Network (WLAN).
While the UE establishes a connection with a 3GPP access network to receive a service, when a traffic overload occurs in the 3GPP access network, it may improve efficiency of an entire network that the UE processes traffic to process through another access network, i.e., a non-3GPP access network. In this way, traffic steering is referred to as steering of traffic or a path of traffic such that traffic may be variably processed through a 3GPP access network and/or a non-GPP access network.
For traffic steering, a policy for interworking of a 3GPP access network and a non-3GPP access network such as Access Network Discovery and Selection Functions (ANDSF) may be set to the UE, and the policy may be managed separately from an interworking policy set by the network.
Information related to traffic steering may be provided through system information. Because system information is generally broadcasted, a size thereof may be limited, and a very large size of system information may be a burden to a system. Information related to traffic steering may include, for example, an identity (ID) of a non-3GPP access network and a size of the ID may be maximum 32 octets.
When the UE reselects a cell, a procedure that updates system information together with information related to traffic steering may be required. Even when the UE reselects a frequency or changes an RRC state, the procedure may be required. In such a case, system information including information related to traffic steering should be able to again updated and thus system efficiency may be deteriorated.